How to solve nonlinear equations?

I need to solve the nonlinear equation:

(x-m1)'Y1(x-m1)=a*(x-m2)'Y2(x-m2)

'm1' and 'm2' are 2-dim vectors, Y1 and Y2 - 2-dim matrices

Of course, there are infinitely many solutions (an ellypse)

i want to plot this ellypse. or part of this ellypse which lays in [-5 5]x[-1 6]

Answer 1

[Walter Roberson]

If you have the symbolic toolkit, then consider ezplot()